Seems interesting. Compared to Long Sword, the upped version is seems relatively well balanced once the drain amount is pegged down.
I see 2 main issues.
1) The unupped should be a little lower in attack than the upped to make upgrading worthwhile
2) Both unupped and upped should have much lower HP.
Note that for Short Sword and Long Sword the stats are 3|2 and 6|2 respectively. This cards HP (8 and 9) are much to high in comparison. So it will be a bit too strong when animated I think. (at 8 / 9 hp this thing is tougher than most other weapons, and even many of the dragons)
Other than that it would make an interesting addition to life. It keeps with the extra tough critter motif.
Is +1-2 ATK really worth a upkeep?
One thing people are missing here is that the upkeep in some situations is actually a benefit.
For instance, Steal, Crusader, Mind Gate, and PU (for animated / flown) will be much less effective since the user will require
quanta to make use of them.
So, in a sense, this weapon has a counter to those spells built into it.
Consider the case of flood (the other card that uses an upkeep for balance). Steal could be used as a destruction mechanism. In that case, the use of the steal card would have their benefit enhanced by the upkeep. In this case, their benefit is detracted from since the card will shorten the length of their use.